Wetting agent



Patented-May 31 1949 WE'ITING AGENT Hans George Figdor, Philadelphia, Pa., assignor to E. F. Houghton and Company, Philadelphia,

Pa., a corporation of Pennsylvania I No Drawing. Application August 15, 1947,

4 Serial No. 768,937 J v 13 Claims. (01. 252-352) The present invention relates to novel surfacea'otive compositions, and more particularly it relates to compositions comprising a blend of two components which cooperate with each other to components.

tingulshed from a reaction product of the two While the water-soluble surfaceactive agent employed in the composition will possess surface activity by itself, it has been found produce a product possessing unexpected superior 5 that by blending the polyethyleneglycol diester wetting and penetrating properties. therewith, the wetting and penetrating power 0! Such surface-active agents, commonly referred the resultin blend is many times greater. This to as wetting agents, are very useful in many inenhancement of these properties was not to be dustries, for example, in the textile industry as expected as the polyethyleneglycol diesters used dye-levelin agents, carbonizing assistants, conin the composition of the present inventionhave trolled-shrinkage assistants, and the like. The limited hydrophilic properties (water-compatiwetting agents on the market today are generally bility). This limited water-compatibility of the classified into three groups: anionic, cationic, and diesters makes them of little value as wetting non-ionic materials. While some of these agents agents. are highly efllcient, that is, they perform well The polyethyleneglycol diesters used in the atvery low concentrations, they are also relapresent invention, as stated, exhibit, as a class, tively expensive. On the other hand, the less exlimited water-compatibility even at room tempensive materials are relatively less eflicient, that perature and less water-compatibility as the temis, they must be present in higher concentrations perature is raised to that normally employed for to perform satisfactorily. 2o wettin penetrating, and the like purposes, for It is, therefore, an object of the present invenexample, from 100 F. to approximately 200 F. tion to provide highly emcient wetting agents Thus, while the esters dissolvein alimited amount from relatively inexpensive raw materials. of water, the solution upon further dilution will 1 A further object of the present invention is to become cloudy and upon still further dilution greatly enhance the efllciency of known wetting the diester will separate as an oil. Similarly, 9. agents. rise in temperature may cause cloudiness or sepa- Another object is to.combine certain diesters ration of the diester. of polyethylene glycols of limited water-compati- The presence of the water-soluble surface-acbility with water-soluble surface-active agents of tive agent in the composition. with a diester, of anionic, cationic, or non-ionic nature, to provide '30 the type that possesses only limited water-comwater dispersiblecompositions of unexpectedly patibility, serves to increase the water-compatiimproved wetting and penetrating. properties. bility of the diester. While, as will hereinafter Other objects will appear hereinafter from be discussed, certain of the diesters are more hya consideration of this specification and the drophillic thanuothers, the presence 01 the waterclaims. soluble surface-active agent with any particular a The wetting agent of the present invention diester will increase its water-compatibility to a comprises a blend of a water-soluble surface-acvery marked extent so that its stability to dilutive agent of the anionic, cationic, or non-ionic tion is much greater than would otherwise be type and a diester of a polyethylene glycol reppossible. For example, even in the case ofthe resented by the following formula: diesters of the least water-compatibility, the o water-soluble surface-active agent functions ih mi therewith to provide a composition which can be wherein n is a number f 5 to inclusive, used in the relatively low concentrations, for ex- R1 and R2 are unsubstituted, saturated alkyl m between about 2% and about (101%, and 'groups, straight or branched chain, thelnumber at the temperatures I Y employed for the of carbon atoms in R1 th number or car treatment of materials Wlth Wetting agents. Furbon atoms in being from 12 to 1 inclusive, thermore, as stated, the wetting and penetrating and the difference between the number of car- P p s of e composition of t Presentinbon atoms in R1 and in R2 being no more than 4'1 vention are greately. e s d. as mpared h novel tti composition of th present either to those of the water-soluble surface-acinvention is prepared by mixing the polyethylene tive agent, or to those of the diester, and are glycol diester and the water-soluble surface-acmark dly greater than was to be exp m a tive agent selected from the group consisting of knowledge of the wetting and penetrating propanionic, cationic, or non-ionic surface-active erties of the two components; in other words a agents. The resulting mixture is a blend as dismuch more efilcient wetting agent is provided;

Referring more specifically to the diester of polyethyleneglycol employed in accordance with the present invention, it is seen from the formula given above that the alcoholic component of the diester is a polyglycol of a chain length of from 6 to 23 recurring ethylene oxide (Cal-I40) units. Such polyethyleneglycols represent an average molecular weight of from about 300 to about 1,000. As stated, the alkyl ester groups represent a total of from 12 to 6 carbon atoms exclusive of the carbon atoms in each carboxyl group, while the difference in chain length between the ester groups does not vary by more than 4 carbon atoms. Thus, the ester groups R1 and R: may contain the same number of carbon atoms in which case R1 and R: will at th'e' same time contain either 6, 7 or 8 carbon atoms. n the other hand, the ester groups R1 and R2 may differ from each other by 1, 2, 3, or 4 carbon atoms. but. as stated the total carbon atoms in the ester groups, represented in the formula by R1 and R: will not be less than 12 nor greater than 16.

The polyglycol diesters used in the preparation of the wetting composition of the invention may be prepared by any desired method, now known or later developed in the art, for example, the diester may be prepared from the polyglycol and the free fatty acid, with or without a dehydrating catalyst; from the polyglycol and the halide of the fatty acid; and from the polyglycol and a low molecular weight ester of the fatty acid by the so-called ester interchange method. Since diesters are used in the composition, the reaction to form the polyglycol ester will involve one mol of the polyglycol and two mols of the material furnishing the acyl groups. It is not necessary to achieve complete esterification for the purpose of the invention, for example, an ester which contains approximately 5% to of free fatty acid is satisfactory for use.

Examples of the fatty acids which may be reacted with the pol lycols, either as such or in the form of the halide or low molecular weight ester or otherwise, are caprylic; pelargonic; ethyl hexylic; caproic; capric; ethy1 butyric; dipropyl acetic; delta isopropyl valeric; isoamyl acetic; n-heptylic (oenantic) valeric; isovaleric; isobutyl ethyl acetic; isoamyl butyl acetic and undecylic. In addition to the acids listed, any other material may be used to provide R1 and R2 within the limits stated in the formula. The material or materials furnishing the R1 and R: groups need not be pure, for example, it is not necessary to use a chemically pure fatty acid, but commercial acids, for example, commercial caprylic acid, which is prepared from cocoanut oil and contains small amounts of other fatty acids, may be used in the preparation of the diester.

The polygiycol reacted with the material or materials which provide the R1 and R2 in the compound may, as shown by the formula, be any polyglycol of 6 to 23 recurring 021140 units and the polyglycol may be a mixture of such polyglycols and may contain amounts of polyglycols of fewer or greater C2H4O units providing the mixture averages between 6 and 23 units. Typical examples of such polyglycols'are those whose C2H4O units are such that the average molecular weight is about 300, 400, 600 and 1,000, namely C2H4O units averaging 6, 9, 13, and 23. (Preferably, the diester will contain on the average of from 9 to 13 recurring ethylene groups.

Using hexaethyleneglycol as typical, although as made clear above, any other polyglycol furnishing the necessary C1840 units may be used in place thereof, the following compounds are illustrative of the diesters used in preparing the composition of the invention; hexaethylene glycol-dicaprylate, hexaethylene glycol-di-pelargonate, hexaethylene glycol-di-Z-ethyl-hexylate, hexaethylene glycol-caprylate-Z-ethyl-hexylate, hexaethylene glycol-caprylate-pelargonate. hexaethylene glycol-z-ethyl hexylate-pelargonate, hexaethylene glycol caproate caprate, hexaethylene glycol 2 ethylbutyrate pelargonate, hexaethylene glycol 2 ethylbutyrate caprate, hexaethylene-glycol-z-ethylbutyrate caprylate, hexaethylene glycol-2-ethy1butyrate 2 ethyl hexylate, hexaethylene glycol di-(dipropyl acetate) hexaethylene glycol-di-(delta lsopropyl valerate) hexaethylene glycol di- (isoamyl acetate), hexaethylene glycol-heptylate-undecylate, hexaethylene glycol isovalerate pelargonate, and hexaethylene glycol-diheptylate. Other examples are those in which polyethylene glycols having an average molecular weight of 400, 600 and up to 1000 are used in place of the hexaethylene glycols used in preparation of the diesters above set forth. Obviously, combinations of two or more of the diesters may be employed with the water-soluble surface-active agents.

Referring to the surface-active agents employed in the composition of the present invention, they, as stated, may be any water-soluble anionic, cationic, or non-ionic compound or material having surface-active properties. Examples of anionic surface-active agents in the form of water-soluble salts are: soaps, such as potassium palmitate, triethanolamine oleate, morpholine stearate, sodium laurate, and ammonium myristate; alkyl benzene sulphonates, such as sodium dodecyl-, keryl-, or tridecylbenzene sulphonates; alkyl diphenyl sulphonates, such as sodium butyl diphenyl sulphonate; alkyl naphthalene sulphonates, such as sodium diisopropyl naphthalene sulphonate, ammonium diamyl naphthalene sulphonate, sodium monononyl naphthalene sulphonate, sodium isopropyl isobutyl naphthalene sulphonate, and sodium dinonyl naphthalene sulphonate; sulphated aliphatic alcohols such as sodium hexadecyl sulphate, sodium oleyl sulphate, triethanolamine dodecyl sulphate, sodium 3-9-diethyl S-tridecanol sulphate, sodium 2-methyl '7-ethyl -undecanol sulphate, and sodium 2-ethyl l-hexanol sulphate; sulphated and sulphonated fatty oils, acids or ester, such as the sodium salt of sulphonated castor oil, the sodium salt of sulphated red oil, the sodium salt, of sulphonated butyl oleate, and the sodium salt of sulphonated isopropyl oleate: alkyl sulpho phthalates, such as sodium hexadecyl sulpho phthalate; sulphated amides, such as sulphated hydroxy-ethyl lauramide and sulphated hydroxy-isopropyl palmitamide; sodium salt of lauryl sulpho acetate; sodium salt of dioctyl sulpho-succinate; sodium salt of oleyl methyl tauride; sodium salt of sulphonated dodecyl benzoate, and the like. Examples of non-ionic surface active agentsare: partial esters of polyhydric alcohols, such as nonaethylene glycol monolaurate, and tricosaethylene glycol monolaurate; condensation products of alkyl phenols with ethylene oxide such as the reaction product of isooctyl phenol with 12 ethylene oxide units; condensation products of alkyl thiophenols with 10 to 15 ethylene oxide units; condensation products of higher fatty alcohols with ethylene oxide such as the reaction products of oleyl alcohol with to or more ethylene oxide units: ethylene oxide addends of monoesters of hexahydric alcohols and inner ethers thereof such as sorbitan monolaurate, sorbitol monooleate and mannitan monopalmitate; the non-ionic reaction products of fatty acids, or their derivatives, with at least two molecules of hydroxylated amines as described in Patent No. 2,089,212; and the like. Examples of cationic surface-active agents are: salts of primary, secondary, and tertiary amines, such as oleyl amine acetate, dodecyl amine acetate, dioctyl amine lactate, stearoyldiethanolamine acetate, and dilauroyl triethylene-tetramine diacetate; and quarternary salts, such as lauryl pyridinium bromide, octodecyl ethyl morphollnium chloride, lauroyl-oxyethyl di-(hydroxy ethyl) ethyl ammonium ethyl sulphate, oleyloxyethyl trimethyl ammonium ethyl sulphate, do-

, decyl trimethyl ammonium chloride, and the like.

, In preparing the composition, the water-soluble surface-active: agent and the polyethyleneglycol diester may be mixed in any desired manner and, r

if desired, the composition prepared for sale may be substantially anhydrous or may contain water, for example, up, to 60% or more. The composition when employed as a wetting agent will, of course, be diluted to provide a solution of relatively low concentration of the surface-active components, for example, 2% to 0.01%. composition may also contain other substituents, for example, inorganic'salts, either added as such or accompanyingv the water-soluble surfaceactive agent. Thus, if the water-soluble surfaceactive agent contains an inorganic salt, such as sodium sulphate, as the result of'its method of preparation, the salt may remain in the blend of the'invention or it may be separated by appro- The ' Thus, whereas 5% of a particular surface-active priate procedures from the surface-active agent either before or after mixing with the polyethylene glycol diester.

As stated above, the blend of polyethylene glycol diester and water-soluble surface-active agent provides a surface-active composition of greatly enhanced and superior properties, making it especially valuable for Wetting, penetrating, and like purposes. .As also stated, the diesters, which are normally relatively incompatible with water at low concentrations, become much more hydrophilic in the presence of the watersoluble surface-active agent, so that the diesters will remain dispersed in much greater dilutions than would otherwise be possible. Likewise, the diester will be much less likely to separate from the aqueous phase when the temperature is raised, for example, to 100 F. or higher. While the diesters used in the composition of the inthe composition comprising the blend of diester and water-soluble surface-active agent will have greatly enhanced water dispersibility, and the presence of the water-soluble surface-active agent in appropriate proportions in the blend will provide a composition which may be diluted to concentrations less than 2% and down to 0.01% with assurance that the diester will not separate from the solution at the temperatures of treatment, usually F. to 200 F., of materials with the composition. While any watersoluble surface-active agent may be used, one characterized by high hydrophilic properties is preferred for use in the composition.

agents, the use of an anionic or non-ionic surface-active agent is generally preferred, rather than a cation-active agent. I p

The relative proportions of the water-soluble surface-active agent mayvary over a wide range, and even as small an amount as 10% of the diester in the blend of diesterand surface-active agent will provide increased wettingactivity. In

, is dispersible in water at concentrations less than 2% and at a temperature of at least 100 F., results. The minimum proportion of the watersoluble'surface-active agent which may be incorporated in the blend to provide a composition of the stated dilutability operative at the stated temperature depends to some extent on the particular diester and water-soluble surface-active agent employed and will not be substantially less than 5%. For example, generally speaking, when a given water-soluble surface-active agent is employed, the minimum amount of the agent required will be in inverse ratio to the length of the polyethylene-oxide chain of the diester.

agent when used witha polyethyleneglycol diester of'an average chain length of 23 recurring ethylene, oxide units may be sufilcient, larger amounts, for example, 20%, may be required when the polyethyleneglycol diester has an average chain of 6 recurring ethylene oxide units. Generally also, the polyethyleneglycol diesters containing branched chain acid residues will require more water-soluble surface-active agent than will a compound having straight chain acid residues. The amount of water-soluble surface-. active agent required to obtain the desireddispersibility of the composition will also depend to someextent on the hydrophilic properties of the agent; that is to say, the amount of, an agent having relatively high hydrophilic properties which will be required will be less than that required when a surface-active agent of less hydrophilic properties is selected.

No difliculties will be presented in preparing a blend of the requisite properties to provide a composition capable of being used in the desired dilution and at the desired temperature. The

relative proportion of diester to water-soluble; surface-active agent in the composition will beadjusted so that the composition will be dispersible in water at the desired concentration and temperature; that is to say, the diester will not separate in any appreciable amount, as an oil, when the composition is used as a wetting agent. The

treating solutions may be 'opalescent, but in the preferred embodiment, the relative proportions of the two components are adjusted so that the solution will remain clear in the dilution desiredand at the temperature of treatment.

From' the foregoing, it will be clear thatthe diester and water-soluble surface-active agent may be present in the composition in an amount Of the. three classes of water-soluble surface-active between 10% of the diester to 90% of the watersoluble surface-active agent and about 95% of of the diester to about of the surface-active agent to provide a, composition which is dispersible in water at concentrations less than 2% and at a temperature of at least 100 F. Advantageously, the relative proportions will be between 20% of the diester to 80% of the water-soluble surface-active agent and 80% of the diester to 20% of the surface-active agent, the relative proportions providing water dispersibility at the stated dilution and temperature.

In the preferred embodiment of the invention, the relative proportions of the diester and water soluble agent within the ranges of proportions given above, will be such that the composition is dispersible in water at concentrations less than 0.5% and at a temperature of at least 140 F. It is to be understood that the proportions of the two components may be adjusted so that the composition will be dispersible in water in concentrations as low as 0.01% and at a temperature as high as 200 F.

Following are three tables which illustrate the features of the present invention. The tables show the wetting speed in seconds in Draves wetting speed tests using varying proportions of a polyethyleneglycol diester and surface-active agents. The polyethyleneglycol diester is, in all three tables, the diester of caprylic acid and a polyethyleneglycol having an average molecular we'ght of 600 (in the tables, the diester is refeired to as tridecaethylene polyglycol dicaprylate). In the first table, the diester is blended with an anionic surface-active agent; in the seccad, with a non-ionic surface-active agent; and i. the third, with a cationic surface-active agent. In the tables and all the examples, the Values were determined. at 100 F., and, unless otherwise specified the percentages given. are on a water-free basis.

TableI In Example A of each table, the solution was cloudy and the diester had a tendency to come out of solution upon standing and it was, therefore, necessary to work with a freshly made sample. In other examples, there wasno tendency for the diester to separate as an oil, even after long standing.

The following examples are intended to illustrate but not limit in any way the novel compositions ofthe present invention:

Example 1.- parts of the esteriflcation product of one molecule hexaethylene glycol with two molecules caprylic acid were mixed with 40 parts of sodium dodecyl sulphate. The Draves test showed the following wetting times:

0.5%, 1 second; 0.2%, 4 seconds. 0.1%, 13 seconds; 0.05%, 38 seconds.

Example 2.- parts of the esteriflcatlon product of one molecule nonaethylene glycol with two molecules 2-ethyl hexylic acid were mixed with 20 parts of sodium dodecyl sulphate. The Draves test showed the following wetting times:

0.5%, instantaneous; 0.2%, 4 seconds. 0.1%, 13 seconds; 0.05%, 44 seconds.

average molecular weight 600 with two molecules of pelargonic acid were mixed with 20 parts of dilauroyltriethylene-tetramine-diacetate (a cation active agent prepared by heating 2 molecules of lauric acid with one molecule of triethylene BOD 'lridceaethylene polyglycol dimprylate, percent Sodium dodecyl sulphate,

percent O Wetting time. seconds:

0.5% at F 7 0.2"} zit 100 F 0.1 27 100 F". 0.05%:it1|)0 F eats a s eats a a same a 2 east e e saws a a ass a a Table 2 Trideeaethylene polyglycol dicaprylate, percent Sorbitan monolaurate-ethylene oxide reaction product (Tm-en 20 of Atlas Powder Company), percent 0 Wetting Time, Seconds:

0.5? I at 100 F l. .2% at 100 F 0.1% at 100 F 0.05% at 100 F sets s a lg over 300 0=instantaneous wetting.

Table 3 GO EE Trideeaethylene polyglycol dicaprylate, percent Lauroyloxycthyl dihydroxyethyl ammonium ethylsulphate. percent 0 Wetting time, seconds:

0.5% at 100 F 7 0.2% at100 F. 0.1% at100 F. 0.05% at 100 F @Ecne 8 5' N 68 over 300 tetramine to 160-190 C. until two molecules of water have split oil and neutralizing the product with glacial acetic acid). The Draves test showed the following wetting times:

0.5%, 2 seconds; 0.2%, 7 seconds. 0.1%, 19 seconds; 0.05%, 62 seconds.

Example 5.66 parts of the esterification product of one molecule of polyethylene glycol of the average molecular weight of 600 with one molecule of 2-ethyl-butyric acid and 1 molecule of 'capric acid were mixed with 34 parts of sulphonated castor oil 75%). The Draves test showed the following wetting times:

0.5%, 3 seconds; 0.2%, 10 seconds. 0.1%, 20 seconds; 0.05%, 134 seconds.-

Example 6.-60 parts of the esteriflcation product of one molecule nonaethylene glycol with one molecule of 2- ethyl hexylic acid and one molecule of pelargonic acid were mixed with 40 parts of the sodium salt of 3.9-diethyl G-tridecanol sulphate. The Drave's test showed the following wetting times:

0.5%, instantaneously; 0.2%, 3 seconds. 0.1%, '1 seconds; 0.05%, 21 seconds.

Example 7I-Tridecaethylene glycol capratecaprylate was mixed with an equal amount of the ethylene oxide addend of isooctyl phenol (containing on the averaged 12 ethylene oxide units).

The Drave's test showed the following wetting times:

0.5%, 1 second; 0.2%, 4 seconds. 0.1%, 8 seconds; 0.05%, 32 seconds Example 8.50 parts of the mixed ester of 2- ethyl butyric and z-ethyl hexylic acid with nonaethylene glycol were mixed with 50 parts of sodium nonyl-naphthalene sulfonate (an anionic surface-active agent). The Drave's test showed the following wetting times:

0.5%, instantaneously; 0.2%, 3 seconds. 0.1%, 9 seconds; 0.05%, 30 seconds.

Example 9.-66 parts of an esteriflcation product of 1 molecule 2-ethyl butyric acid and 1 molecule pelargonic acid with 1 molecule polyethylene glycol (average molecular weight 600) were mixed with 34 parts of sodium keryl henzene sulfonate (an anionic surface-active agent).

The Drave's test showed the following wetting times:

0.5%, 3 seconds; 0.2%, 6 seconds.

0.1%, 18 seconds; 0.05%, 51 seconds.

Example 10.95 parts of the esterification product of 1 molecule capryllc acid, '1 molecule 2-ethyl hexylic acid and 1 molecule polyethylene glycol (average molecular weight 600) were mixed with 5 parts at the sodium salt of di (2-ethyl hexyl) sulpho succinate. The Drave's test showed the following wetting times: I

0.5%, instantaneously; 0.2%, 4 seconds.

0.1%, '7 seconds: 0.05%, 15 seconds.

Example 11.80 parts of an esterlflcation product of 2 molecules n-heptylic acid (oenantic acid) with one molecule of nonaethylene glycol were mixed with 20 parts sodium dodecyl sulfate (an anionic surface-active agent). The Drave's test showed the following wetting times:

0.5, 2 seconds; 0.2%, 4 seconds. 0.1%, 11 seconds;'0.05%, 41 seconds.

di-heptylate were mixed with.60 parts of the ethylene oxide addend of nonyl thiophenol (containing between 10 and 15 ethylene oxide units). The Drave's test showed the following wetting times:

0.5%, instantaneous; 0.2%, 2 seconds. 0.1%, 4 seconds; 0.05%, 14 seconds.

Example 13.- parts of an esterification product of 2 molecules delta-methyl caproic acid (also called isoamyl acetic acid) and 1 molecule of a polyethylene glycol of anaverage molecular weight of 600 were mixed with 20 parts of sodium dodecyl benzene sulphonate. The Drave's test showed the following wetting times:

0.5, instantaneously; 0.2%, 2-seconds. 0.1%, 7 seconds; 0.05%, 45 seconds.

Example -60 parts of nonaethylene glycolheptylate-delta-methyl caproate were mixed with 40 parts of sodium 2-methyl '7-ethyl 4-undecanol sulphate. The Drave's test showed the following wetting times:

The Drave's test applied to the sodium petroleum sulphonate alone gave the following wetting times:

0.5%; 45 seconds; 0.2%, 131 seconds. 0.1 no wetting power; 0.05 no wetting power.

From the foregoing, it will be seen that there are a wide variety of materials and combinations that may be employed in accordance with the invention. In many cases, it will be desirable to employ a polyethylene glycol diester in which R1 and R2 are of equal length, for example 7, and in which the number of ethylene oxide averages 9m 13. Typicalexamples of these are polyethylene glycol-dicaprylate or poly- .ethylene glycol-di(2-ethylhexylate) in which 0 the ethylene oxide units average 9 or 13. These esters may advantageously be employed with an anionic surface-active agent. Typical examples are a blend of polyethylene glycol di-caprylate having ethylene oxide units averaging 9 or 13 with a water-soluble sulphated alcohol of the type above listed or a blend of polyethylene glycol di(2-ethylhexylate) with a water-soluble salt of an alkylated naphthalene sulphonate of the type above set forth.

Considerable modification is possible in the selection of the surface-active agent and diester and in the various combinations thereof without departing from the essential features of the invention.

I claim:

1. As a wetting agent a blend of water-soluble surface-active agent and a polyethyleneglycol diester represented by the following formula:

wherein n is a number from 5 to 22 inclusive, R1 and R2 are unsubstituted, saturated alkyl groups, the number of carbon atoms in R1 plus the num- Example 12.40 parts of nonaethylene glycol 75 her of carbon atoms in R2 being from 12 to 16 inelusive, and the diflerence between the number of carbon atoms in R1 and in R2 being no more than 4, the relative amounts of said water-soluble surface-active agent and diester, based on the combined weight thereof, being between 10% and about 95% of said polyethyleneglycol diester and between about 5% and 90% of said surface-active agent to provide a composition dispersible in water at concentrations less than about 2% and at a temperature of at least about 100 F.

2. The wetting agent of claim 1, wherein n is a number between 8 and 12 inclusive.

3. The wetting agent of claim 1, wherein R1 and R2 are alkyl groups containing the same number of carbon'atoms.

4. The wetting agent of claim 1, wherein n is a number between 8 and 12 inclusive, and wherein R1 and R2 are alkyl groups containing the same number of carbon atoms.

5. The wetting agent of claim 4, wherein R1 and R2 are alkyl groups containing 7 carbon atoms.

6. The wetting agent of claim 1, wherein the water-soluble surface-active agent is of the anionic type.

7. The wetting agent of claim 6, wherein the water-soluble surface-active agent is a watersoluble salt of a sulphated aliphatic alcohol.

8. The wetting agent of claim 1, wherein the water-soluble surface-active agent is of the nonionic type.

9. The wetting agent of claim 1, wherein the relative amounts of said surface-active agent and said diester, based on the combined weight thereof, are between 20% and 80% of the diester and between 80% and 20% of the surface-active agent to provide a composition dispersible in water at concentrations less than about .5% and at a temperature of at least about 140 F.

10. The wetting agent of claim 9, wherein the water-soluble surface-active agent is of the anionic type.

11. As a wetting agent a blend of polyethyleneglycol-dicaprylate, the number of ethylene oxide units averagin 9, and a water-soluble salt of a sulphated aliphatic alcohol, the relative amounts of the two components, based on the combined weight thereof, being between 10% and about 95% of the former and about 5% and of the the latter, to provide a composition dispersible in water at concentrations less than about 2% and at a temperature of at least about 100 F.

12. As a wetting agent a blend of polyethyleneglycol-dicaprylate, the number of ethylene oxide units averaging 13, and a water-soluble salt of a sulphated aliphatic alcohol, the relative amounts of the two components, based on the combined weight thereof, being between 10% and about of the former and about 5% and 90% of the latter, to provide a composition dispersible in water at concentrations less than about 2% and at a temperature of at least about F.

13. As a wetting agent a blend of polyethyleneglycol-di(2-ethyl hexylate), the number of ethylene oxide units averaging 13, and a water-soluble salt of an alkylated naphthalene sulphonate, the relative amounts of the two components, based on the combined weight thereof, being between 10% and about 95% of the former and about 5% and 90% of the latter, to provide a composition dispersible in water at concentrations less than about 2% and at a temperature of at least about 100 F.

HANS GEORGE FIGDOR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name 1 Date 2,174,760 Schuette et al Oct. 3, 1939 2,269,529 Goldsmith Jan. 13, 1942 2,418,664 Ramsey Apr. 8, 1947 

